Uniform Airflow Migration Strategy

updated: 2017-07-27 13:37

Uniform Airflow Migration Strategy¶

Synopsis¶

display name: uniform_airflow

goal: airflow_optimization

[PoC]Uniform Airflow using live migration

Description

It is a migration strategy based on the airflow of physical servers. It generates solutions to move VM whenever a server’s airflow is higher than the specified threshold.

Requirements

Hardware: compute node with NodeManager 3.0 support
Software: Ceilometer component ceilometer-agent-compute running in each compute node, and Ceilometer API can report such telemetry “airflow, system power, inlet temperature” successfully.
You must have at least 2 physical compute nodes to run this strategy

Limitations

This is a proof of concept that is not meant to be used in production.
We cannot forecast how many servers should be migrated. This is the reason why we only plan a single virtual machine migration at a time. So it’s better to use this algorithm with CONTINUOUS audits.
It assumes that live migrations are possible.

Requirements¶

This strategy has a dependency on the server having Intel’s Power Node Manager 3.0 or later enabled.

Metrics¶

The uniform_airflow strategy requires the following metrics:

metric	service name	plugins
`hardware.ipmi.node.airflow`	ceilometer	IPMI
`hardware.ipmi.node.temperature`	ceilometer	IPMI
`hardware.ipmi.node.power`	ceilometer	IPMI

Cluster data model¶

Default Watcher’s Compute cluster data model:

Nova cluster data model collector

The Nova cluster data model collector creates an in-memory representation of the resources exposed by the compute service.

Actions¶

Default Watcher’s actions:

action description
migration
Migrates a server to a destination nova-compute host

This action will allow you to migrate a server to another compute destination host. Migration type ‘live’ can only be used for migrating active VMs. Migration type ‘cold’ can be used for migrating non-active VMs as well active VMs, which will be shut down while migrating.

The action schema is:
schema = Schema({
 'resource_id': str,  # should be a UUID
 'migration_type': str,  # choices -> "live", "cold"
 'destination_node': str,
 'source_node': str,
})
The resource_id is the UUID of the server to migrate. The source_node and destination_node parameters are respectively the source and the destination compute hostname (list of available compute hosts is returned by this command: nova service-list --binary nova-compute).

action	description
`migration`	Migrates a server to a destination nova-compute host This action will allow you to migrate a server to another compute destination host. Migration type ‘live’ can only be used for migrating active VMs. Migration type ‘cold’ can be used for migrating non-active VMs as well active VMs, which will be shut down while migrating. The action schema is: schema = Schema({ 'resource_id': str, # should be a UUID 'migration_type': str, # choices -> "live", "cold" 'destination_node': str, 'source_node': str, }) The resource_id is the UUID of the server to migrate. The source_node and destination_node parameters are respectively the source and the destination compute hostname (list of available compute hosts is returned by this command: `nova service-list --binary nova-compute`).

Planner¶

Default Watcher’s planner:

Weight planner implementation

This implementation builds actions with parents in accordance with weights. Set of actions having a higher weight will be scheduled before the other ones. There are two config options to configure: action_weights and parallelization.

Limitations

This planner requires to have action_weights and parallelization configs tuned well.

Configuration¶

Strategy parameters are:

parameter	type	default Value	description
`threshold_airflow`	Number	400.0	Airflow threshold for migration Unit is 0.1CFM
`threshold_inlet_t`	Number	28.0	Inlet temperature threshold for migration decision
`threshold_power`	Number	350.0	System power threshold for migration decision
`period`	Number	300	Aggregate time period of ceilometer

Efficacy Indicator¶

None

Algorithm¶

For more information on the Uniform Airflow Migration Strategy please refer to: https://specs.openstack.org/openstack/watcher-specs/specs/newton/implemented/uniform-airflow-migration-strategy.html

How to use it ?¶

$ openstack optimize audittemplate create \
  at1 airflow_optimization --strategy uniform_airflow

$ openstack optimize audit create -a at1 -p threshold_airflow=410 \
       -p threshold_inlet_t=29.0 -p threshold_power=355.0 -p period=310

External Links¶

Intel Power Node Manager 3.0

updated: 2017-07-27 13:37

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